This Core is a central morphology facility, which provides support for the individual investigators who ocmprise this Program Project. The services provided include routine light microscopy (H&E) processing, analysis of tissue sections, and special stains. In addition, when desired by the investigators, ultrastructural, immunofluorescence, immunohistochemistry, and morphometic analysis services are available. Finally, this core provides important digital image analysis and graphic illustration support for the investigators. In the past this core has received heavy usage and it is anticipated that demand will continue to increase. For example, during the past year over 1276 samples were processed to support the studies carried out in this Program Project. Of this total, there were 975 samples submitted for light microscopy analysis (H&E), 931 blanks were cut for imunohistochemistry and/or immunoflurescence, and 58 were processed for special stains. In addition last year 124 samples were processed for TEM. We anticipate that this Core will continue to play an active role in the Program Project and the investigators will extensively use the services of the morphology core. For example, each of the specific projects will routinely utilize light microscopy to monitor the intensity and cellularity of the lung injury in the various experimental models. Morphometric analysis of tissue sections will be used to quantitate lung injury with a variety of parameters measured, including the developing size of lung granulomas, percent alveolar and endothelial cell injury and quantitation of leukocytes and hemorrhage in the alveolar space. In specific studies of in vivo specimens and in vitro cultured cells will be assessed by immunohistochemical analysis. Frozen sections of these tissues and cells will be assessed for the protein of a variety of cytokines that are likely to be expressed and serve as mechanisms for the progression of lung inflammation. This is the only technical Core requested for this Program Project and is the main supporting mechanism for the morphology associated with the various sections. The activity of this Core is of critical importance to the success of the Program Project. This Core also offers digital image analysis and graphic services, including color digital laser printing for posters and publications for the investigators and their team of researchers associated with this Program Project.